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                        Python高级
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                            <b>1.</b>
                        
                        Python语法高级专题1
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                        GIL问题
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                        赋值-浅拷贝-深拷贝
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                        import导入模块
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                            <b>1.4.</b>
                        
                        总结
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                            <b>2.</b>
                        
                        Python语法高级专题2
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                        多继承和MRO顺序
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                            <b>2.2.</b>
                        
                        property属性
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                            <b>2.3.</b>
                        
                        魔法属性和方法
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                            <b>2.4.</b>
                        
                        with管理上下文
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                            <b>2.5.</b>
                        
                        总结
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                            <b>3.</b>
                        
                        Python语法之装饰器
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                            <b>3.1.</b>
                        
                        闭包
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                            <b>3.2.</b>
                        
                        装饰器
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                            <b>3.3.</b>
                        
                        总结
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                            <b>4.</b>
                        
                        MySQL数据库基本操作
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                            <b>4.1.</b>
                        
                        数据库概述
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                            <b>4.2.</b>
                        
                        数据完整性
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                            <b>4.3.</b>
                        
                        图形化客户端Navicat
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                            <b>4.4.</b>
                        
                        命令行客户端SQL的使用
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                            <b>4.4.1.</b>
                        
                        登录和退出数据库
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                            <b>4.4.2.</b>
                        
                        表结构的操作
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                            <b>4.4.3.</b>
                        
                        数据库的操作
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                            <b>4.4.4.</b>
                        
                        表数据的操作
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                            <b>4.5.</b>
                        
                        知识总结
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                            <b>5.</b>
                        
                        MYSQL数据库进阶操作
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                            <b>5.1.</b>
                        
                        练习强化
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                            <b>5.2.</b>
                        
                        条件
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                            <b>5.3.</b>
                        
                        排序
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                            <b>5.4.</b>
                        
                        分页
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                            <b>5.5.</b>
                        
                        聚合函数
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                            <b>5.6.</b>
                        
                        分组
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                            <b>5.7.</b>
                        
                        连接
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                            <b>5.8.</b>
                        
                        自连接
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                            <b>5.9.</b>
                        
                        子查询
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                            <b>5.10.</b>
                        
                        总结
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                            <b>6.</b>
                        
                        MYSQL数据库编程
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                            <b>6.1.</b>
                        
                        数据准备
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                            <b>6.2.</b>
                        
                        SQL演练
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                            <b>6.3.</b>
                        
                        数据库设计
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                            <b>6.4.</b>
                        
                        数据库编程
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                            <b>6.5.</b>
                        
                        总结
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                            <b>7.</b>
                        
                        MySQL数据库高级用法
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                            <b>7.1.</b>
                        
                        视图
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                            <b>7.2.</b>
                        
                        事务
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                            <b>7.3.</b>
                        
                        索引
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                            <b>7.4.</b>
                        
                        用户管理
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                            <b>7.5.</b>
                        
                        主从配置
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                            <b>7.6.</b>
                        
                        总结
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                            <b>8.</b>
                        
                        miniweb框架
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                            <b>8.1.</b>
                        
                        框架概念
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                            <b>8.2.</b>
                        
                        实现一个简单的框架
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                            <b>8.3.</b>
                        
                        模板替换
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                            <b>8.4.</b>
                        
                        路由概念
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                            <b>8.5.</b>
                        
                        股票收藏夹
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                            <b>8.6.</b>
                        
                        复习
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    f.close()
</code></pre>
<p>&#x8FD9;&#x6837;&#x5199;&#x6709;&#x4E00;&#x4E2A;&#x6F5C;&#x5728;&#x7684;&#x95EE;&#x9898;&#xFF0C;&#x5982;&#x679C;&#x5728;&#x8C03;&#x7528; write &#x7684;&#x8FC7;&#x7A0B;&#x4E2D;&#xFF0C;&#x51FA;&#x73B0;&#x4E86;&#x5F02;&#x5E38;&#x8FDB;&#x800C;&#x5BFC;&#x81F4;&#x540E;&#x7EED;&#x4EE3;&#x7801;&#x65E0;&#x6CD5;&#x7EE7;&#x7EED;&#x6267;&#x884C;&#xFF0C;close &#x65B9;&#x6CD5;&#x65E0;&#x6CD5;&#x88AB;&#x6B63;&#x5E38;&#x8C03;&#x7528;&#xFF0C;&#x56E0;&#x6B64;&#x8D44;&#x6E90;&#x5C31;&#x4F1A;&#x4E00;&#x76F4;&#x88AB;&#x8BE5;&#x7A0B;&#x5E8F;&#x5360;&#x7528;&#x8005;&#x91CA;&#x653E;&#x3002;&#x90A3;&#x4E48;&#x8BE5;&#x5982;&#x4F55;&#x6539;&#x8FDB;&#x4EE3;&#x7801;&#x5462;&#xFF1F;</p>
<p>&#x5BF9;&#x4E8E;&#x7CFB;&#x7EDF;&#x8D44;&#x6E90;&#x5982;&#x6587;&#x4EF6;&#x3001;&#x6570;&#x636E;&#x5E93;&#x8FDE;&#x63A5;&#x3001;socket &#x800C;&#x8A00;&#xFF0C;&#x5E94;&#x7528;&#x7A0B;&#x5E8F;&#x6253;&#x5F00;&#x8FD9;&#x4E9B;&#x8D44;&#x6E90;&#x5E76;&#x6267;&#x884C;&#x5B8C;&#x4E1A;&#x52A1;&#x903B;&#x8F91;&#x4E4B;&#x540E;&#xFF0C;&#x5FC5;&#x987B;&#x505A;&#x7684;&#x4E00;&#x4EF6;&#x4E8B;&#x5C31;&#x662F;&#x8981;&#x5173;&#x95ED;&#xFF08;&#x65AD;&#x5F00;&#xFF09;&#x8BE5;&#x8D44;&#x6E90;&#x3002;</p>
<p>&#x6BD4;&#x5982; Python &#x7A0B;&#x5E8F;&#x6253;&#x5F00;&#x4E00;&#x4E2A;&#x6587;&#x4EF6;&#xFF0C;&#x5F80;&#x6587;&#x4EF6;&#x4E2D;&#x5199;&#x5185;&#x5BB9;&#xFF0C;&#x5199;&#x5B8C;&#x4E4B;&#x540E;&#xFF0C;&#x5C31;&#x8981;&#x5173;&#x95ED;&#x8BE5;&#x6587;&#x4EF6;&#xFF0C;&#x5426;&#x5219;&#x4F1A;&#x51FA;&#x73B0;&#x4EC0;&#x4E48;&#x60C5;&#x51B5;&#x5462;&#xFF1F;&#x6781;&#x7AEF;&#x60C5;&#x51B5;&#x4E0B;&#x4F1A;&#x51FA;&#x73B0; &quot;Too many open files&quot; &#x7684;&#x9519;&#x8BEF;&#xFF0C;&#x56E0;&#x4E3A;&#x7CFB;&#x7EDF;&#x5141;&#x8BB8;&#x4F60;&#x6253;&#x5F00;&#x7684;&#x6700;&#x5927;&#x6587;&#x4EF6;&#x6570;&#x91CF;&#x662F;&#x6709;&#x9650;&#x7684;&#x3002;&#x603B;&#x4E4B;&#xFF0C;&#x80FD;&#x591F;&#x5C06;&#x6253;&#x5F00;&#x4F7F;&#x7528;&#x7684;&#x8D44;&#x6E90; &#x8FDB;&#x884C;&#x81EA;&#x52A8;&#x5173;&#x95ED;&#x662F;&#x4E00;&#x4E2A;&#x975E;&#x5E38;&#x4E0D;&#x9519;&#x7684;&#x624B;&#x6BB5;&#x3002;</p>
<p>&#x540C;&#x6837;&#xFF0C;&#x5BF9;&#x4E8E;&#x6570;&#x636E;&#x5E93;&#xFF0C;&#x5982;&#x679C;&#x8FDE;&#x63A5;&#x6570;&#x8FC7;&#x591A;&#x800C;&#x6CA1;&#x6709;&#x53CA;&#x65F6;&#x5173;&#x95ED;&#x7684;&#x8BDD;&#xFF0C;&#x5C31;&#x53EF;&#x80FD;&#x4F1A;&#x51FA;&#x73B0; &quot;Can not connect to MySQL server Too many connections&quot;&#xFF0C;&#x56E0;&#x4E3A;&#x6570;&#x636E;&#x5E93;&#x8FDE;&#x63A5;&#x662F;&#x4E00;&#x79CD;&#x975E;&#x5E38;&#x6602;&#x8D35;&#x7684;&#x8D44;&#x6E90;&#xFF0C;&#x4E0D;&#x53EF;&#x80FD;&#x65E0;&#x9650;&#x5236;&#x7684;&#x88AB;&#x521B;&#x5EFA;&#x3002;</p>
<p>&#x4E0B;&#x9762;&#x7684;&#x4EE3;&#x7801;&#x8003;&#x8651;&#x4E86;&#x6587;&#x4EF6;&#x5728;&#x4F7F;&#x7528;&#x8FC7;&#x7A0B;&#x4E2D;&#x53D1;&#x751F;&#x5F02;&#x5E38;&#x7684;&#x60C5;&#x51B5;</p>
<pre><code class="lang-python"><span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">m2</span><span class="hljs-params">()</span>:</span>
    f = open(<span class="hljs-string">&quot;output.txt&quot;</span>, <span class="hljs-string">&quot;w&quot;</span>)
    <span class="hljs-keyword">try</span>:
        f.write(<span class="hljs-string">&quot;python&#x4E4B;&#x7985;&quot;</span>)
    <span class="hljs-keyword">except</span> IOError:
        print(<span class="hljs-string">&quot;oops error&quot;</span>)
    <span class="hljs-keyword">finally</span>:
        f.close()
</code></pre>
<p>&#x6539;&#x826F;&#x7248;&#x672C;&#x7684;&#x7A0B;&#x5E8F;&#x662F;&#x5BF9;&#x53EF;&#x80FD;&#x53D1;&#x751F;&#x5F02;&#x5E38;&#x7684;&#x4EE3;&#x7801;&#x5904;&#x8FDB;&#x884C; try &#x6355;&#x83B7;&#xFF0C;&#x4F7F;&#x7528; try/finally &#x8BED;&#x53E5;&#xFF0C;&#x8BE5;&#x8BED;&#x53E5;&#x8868;&#x793A;&#x5982;&#x679C;&#x5728; try &#x4EE3;&#x7801;&#x5757;&#x4E2D;&#x7A0B;&#x5E8F;&#x51FA;&#x73B0;&#x4E86;&#x5F02;&#x5E38;&#xFF0C;&#x540E;&#x7EED;&#x4EE3;&#x7801;&#x5C31;&#x4E0D;&#x518D;&#x6267;&#x884C;&#xFF0C;&#x800C;&#x76F4;&#x63A5;&#x8DF3;&#x8F6C;&#x5230; except &#x4EE3;&#x7801;&#x5757;&#x3002;&#x800C;&#x65E0;&#x8BBA;&#x5982;&#x4F55;&#xFF0C;finally &#x5757;&#x7684;&#x4EE3;&#x7801;&#x6700;&#x7EC8;&#x90FD;&#x4F1A;&#x88AB;&#x6267;&#x884C;&#x3002;&#x56E0;&#x6B64;&#xFF0C;&#x53EA;&#x8981;&#x628A; close &#x653E;&#x5728; finally &#x4EE3;&#x7801;&#x4E2D;&#xFF0C;&#x6587;&#x4EF6;&#x5C31;&#x4E00;&#x5B9A;&#x4F1A;&#x5173;&#x95ED;&#x3002;</p>
<p>&#x6765;&#x770B;&#x770B;&#x5982;&#x4F55;&#x4F7F;&#x7528;with&#x81EA;&#x52A8;&#x5173;&#x95ED;&#x4E00;&#x4E2A;&#x6587;&#x4EF6;&#x3002;</p>
<pre><code class="lang-python"><span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">m3</span><span class="hljs-params">()</span>:</span>
    <span class="hljs-keyword">with</span> open(<span class="hljs-string">&quot;output.txt&quot;</span>, <span class="hljs-string">&quot;r&quot;</span>) <span class="hljs-keyword">as</span> f:
        f.write(<span class="hljs-string">&quot;Python&#x4E4B;&#x7985;&quot;</span>)
</code></pre>
<p>&#x4E00;&#x79CD;&#x66F4;&#x52A0;&#x7B80;&#x6D01;&#x3001;&#x4F18;&#x96C5;&#x7684;&#x65B9;&#x5F0F;&#x5C31;&#x662F;&#x7528; with &#x5173;&#x952E;&#x5B57;&#x3002;open &#x65B9;&#x6CD5;&#x7684;&#x8FD4;&#x56DE;&#x503C;&#x8D4B;&#x503C;&#x7ED9;&#x53D8;&#x91CF; f&#xFF0C;&#x5F53;&#x79BB;&#x5F00; with &#x4EE3;&#x7801;&#x5757;&#x7684;&#x65F6;&#x5019;&#xFF0C;&#x7CFB;&#x7EDF;&#x80FD;&#x591F;&#x81EA;&#x52A8;&#x8C03;&#x7528; f.close() &#x65B9;&#x6CD5;&#xFF0C;&#x90A3;&#x4E48;&#x5B83;&#x7684;&#x5B9E;&#x73B0;&#x539F;&#x7406;&#x662F;&#x4EC0;&#x4E48;&#xFF1F;&#x5728;&#x8BB2; with &#x7684;&#x539F;&#x7406;&#x524D;&#x8981;&#x6D89;&#x53CA;&#x5230;&#x53E6;&#x5916;&#x4E00;&#x4E2A;&#x6982;&#x5FF5;&#xFF0C;&#x5C31;&#x662F;&#x4E0A;&#x4E0B;&#x6587;&#x7BA1;&#x7406;&#x5668;&#xFF08;Context Manager&#xFF09;&#x3002;</p>
<h2 id="53-&#x4E0A;&#x4E0B;&#x6587;context&#x6982;&#x5FF5;">5.3 &#x4E0A;&#x4E0B;&#x6587;(context)&#x6982;&#x5FF5;</h2>
<blockquote>
<p>&#x4E0A;&#x4E0B;&#x6587;&#x5728;&#x4E0D;&#x540C;&#x7684;&#x5730;&#x65B9;&#x8868;&#x793A;&#x4E0D;&#x540C;&#x7684;&#x542B;&#x4E49;&#xFF0C;&#x8981;&#x611F;&#x6027;&#x7406;&#x89E3;&#x3002;context&#x5176;&#x5B9E;&#x8BF4;&#x767D;&#x4E86;&#xFF0C;&#x548C;&#x6587;&#x7AE0;&#x7684;&#x4E0A;&#x4E0B;&#x6587;&#x662F;&#x4E00;&#x4E2A;&#x610F;&#x601D;&#xFF0C;&#x5728;&#x901A;&#x4FD7;&#x4E00;&#x70B9;&#xFF0C;&#x6211;&#x89C9;&#x5F97;&#x53EB;&#x73AF;&#x5883;&#x66F4;&#x597D;&#x3002;....</p>
<p>&#x6797;&#x51B2;&#x5927;&#x53EB;&#x4E00;&#x58F0;&#x201C;&#x554A;&#x4E5F;&#xFF01;&#x201D;....</p>
<p>&#x95EE;:&#x8FD9;&#x53E5;&#x8BDD;&#x6797;&#x51B2;&#x7684;&#x201C;&#x554A;&#x4E5F;&#x201D;&#x8868;&#x8FBE;&#x4E86;&#x6797;&#x51B2;&#x600E;&#x6837;&#x7684;&#x5FC3;&#x91CC;&#xFF1F;</p>
<p>&#x7B54;:&#x554A;&#x4F60;&#x5988;&#x4E2A;&#x5934;&#x554A;&#xFF01;</p>
<p>&#x770B;&#xFF0C;&#x4E00;&#x7BC7;&#x6587;&#x7AE0;&#xFF0C;&#x7ED9;&#x4F60;&#x6458;&#x5F55;&#x4E00;&#x6BB5;&#xFF0C;&#x6CA1;&#x524D;&#x6CA1;&#x540E;&#xFF0C;&#x4F60;&#x8BFB;&#x4E0D;&#x61C2;&#xFF0C;&#x56E0;&#x4E3A;&#x6709;&#x8BED;&#x5883;&#xFF0C;&#x5C31;&#x662F;&#x8BED;&#x8A00;&#x73AF;&#x5883;&#x5B58;&#x5728;&#xFF0C;&#x4E00;&#x6BB5;&#x8BDD;&#x8BF4;&#x4E86;&#x4EC0;&#x4E48;&#xFF0C;&#x8981;&#x901A;&#x8FC7;&#x4E0A;&#x4E0B;&#x6587;(&#x6587;&#x7AE0;&#x7684;&#x4E0A;&#x4E0B;&#x6587;)&#x6765;&#x63A8;&#x65AD;&#x3002;</p>
<p>app&#x70B9;&#x51FB;&#x4E00;&#x4E2A;&#x6309;&#x94AE;&#x8FDB;&#x5165;&#x4E00;&#x4E2A;&#x65B0;&#x7684;&#x754C;&#x9762;&#xFF0C;&#x4E5F;&#x8981;&#x4FDD;&#x5B58;&#x4F60;&#x662F;&#x5728;&#x54EA;&#x4E2A;&#x5C4F;&#x5E55;&#x8DF3;&#x8FC7;&#x6765;&#x7684;&#x7B49;&#x7B49;&#x4FE1;&#x606F;&#xFF0C;&#x4EE5;&#x4FBF;&#x4F60;&#x70B9;&#x51FB;&#x8FD4;&#x56DE;&#x7684;&#x65F6;&#x5019;&#x80FD;&#x6B63;&#x786E;&#x8DF3;&#x56DE;&#xFF0C;&#x5982;&#x679C;&#x4E0D;&#x5B58;&#x80AF;&#x5B9A;&#x5C31;&#x65E0;&#x6CD5;&#x6B63;&#x786E;&#x8DF3;&#x56DE;&#x4E86;&#x3002;</p>
<p>&#x770B;&#x8FD9;&#x4E9B;&#x90FD;&#x662F;&#x4E0A;&#x4E0B;&#x6587;&#x7684;&#x5178;&#x578B;&#x4F8B;&#x5B50;&#xFF0C;&#x7406;&#x89E3;&#x6210;&#x73AF;&#x5883;&#x5C31;&#x53EF;&#x4EE5;&#xFF0C;(&#x800C;&#x4E14;&#x4E0A;&#x4E0B;&#x6587;&#x867D;&#x7136;&#x53EB;&#x4E0A;&#x4E0B;&#x6587;&#xFF0C;&#x4F46;&#x662F;&#x7A0B;&#x5E8F;&#x91CC;&#x9762;&#x4E00;&#x822C;&#x90FD;&#x53EA;&#x6709;&#x4E0A;&#x6587;&#x800C;&#x5DF2;&#xFF0C;&#x53EA;&#x662F;&#x53EB;&#x7684;&#x597D;&#x542C;&#x53EB;&#x4E0A;&#x4E0B;&#x6587;&#x3002;&#x3002;&#x8FDB;&#x7A0B;&#x4E2D;&#x65AD;&#x5728;&#x64CD;&#x4F5C;&#x7CFB;&#x7EDF;&#x4E2D;&#x662F;&#x6709;&#x4E0A;&#x6709;&#x4E0B;&#x7684;&#xFF0C;&#x4E0D;&#x8FC7;&#x4E0D;&#x8FD9;&#x4E2A;&#x9AD8;&#x6DF1;&#x7684;&#x95EE;&#x9898;&#x5C31;&#x4E0D;&#x8981;&#x6DF1;&#x7A76;&#x4E86;&#x3002;&#x3002;&#x3002;)</p>
</blockquote>
<h2 id="54-&#x4E0A;&#x4E0B;&#x6587;&#x7BA1;&#x7406;&#x5668;">5.4 &#x4E0A;&#x4E0B;&#x6587;&#x7BA1;&#x7406;&#x5668;</h2>
<p>&#x4E0A;&#x4E0B;&#x6587;&#x7BA1;&#x7406;&#x5668;&#x672C;&#x8D28;&#x5C31;&#x662F;&#x80FD;&#x591F;&#x652F;&#x6301;with&#x64CD;&#x4F5C;&#x3002;</p>
<p>&#x4EFB;&#x4F55;&#x5B9E;&#x73B0;&#x4E86; __enter__() &#x548C; __exit__() &#x65B9;&#x6CD5;&#x7684;&#x5BF9;&#x8C61;&#x90FD;&#x53EF;&#x79F0;&#x4E4B;&#x4E3A;&#x4E0A;&#x4E0B;&#x6587;&#x7BA1;&#x7406;&#x5668;&#xFF0C;&#x4E0A;&#x4E0B;&#x6587;&#x7BA1;&#x7406;&#x5668;&#x5BF9;&#x8C61;&#x53EF;&#x4EE5;&#x4F7F;&#x7528; with &#x5173;&#x952E;&#x5B57;&#x3002;&#x663E;&#x7136;&#xFF0C;&#x6587;&#x4EF6;&#xFF08;file&#xFF09;&#x5BF9;&#x8C61;&#x4E5F;&#x5B9E;&#x73B0;&#x4E86;&#x4E0A;&#x4E0B;&#x6587;&#x7BA1;&#x7406;&#x5668;&#x534F;&#x8BAE;&#x3002;</p>
<p>&#x90A3;&#x4E48;&#x6587;&#x4EF6;&#x5BF9;&#x8C61;&#x662F;&#x5982;&#x4F55;&#x5B9E;&#x73B0;&#x8FD9;&#x4E24;&#x4E2A;&#x65B9;&#x6CD5;&#x7684;&#x5462;&#xFF1F;&#x6211;&#x4EEC;&#x53EF;&#x4EE5;&#x6A21;&#x62DF;&#x5B9E;&#x73B0;&#x4E00;&#x4E2A;&#x81EA;&#x5DF1;&#x7684;&#x6587;&#x4EF6;&#x7C7B;&#xFF0C;&#x8BA9;&#x8BE5;&#x7C7B;&#x5B9E;&#x73B0; __enter__() &#x548C; __exit__() &#x65B9;&#x6CD5;&#x3002;</p>
<pre><code class="lang-python"><span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">File</span><span class="hljs-params">()</span>:</span>

    <span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">__init__</span><span class="hljs-params">(self, filename, mode)</span>:</span>
        self.filename = filename
        self.mode = mode

    <span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">__enter__</span><span class="hljs-params">(self)</span>:</span>
        print(<span class="hljs-string">&quot;entering&quot;</span>)
        self.f = open(self.filename, self.mode)
        <span class="hljs-keyword">return</span> self.f

    <span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">__exit__</span><span class="hljs-params">(self, *args)</span>:</span>
        print(<span class="hljs-string">&quot;will exit&quot;</span>)
        self.f.close()
</code></pre>
<p>__enter__() &#x65B9;&#x6CD5;&#x8FD4;&#x56DE;&#x8D44;&#x6E90;&#x5BF9;&#x8C61;&#xFF0C;&#x8FD9;&#x91CC;&#x5C31;&#x662F;&#x4F60;&#x5C06;&#x8981;&#x6253;&#x5F00;&#x7684;&#x90A3;&#x4E2A;&#x6587;&#x4EF6;&#x5BF9;&#x8C61;&#xFF0C;__exit__() &#x65B9;&#x6CD5;&#x5904;&#x7406;&#x4E00;&#x4E9B;&#x6E05;&#x9664;&#x5DE5;&#x4F5C;&#x3002;</p>
<p>&#x56E0;&#x4E3A; File &#x7C7B;&#x5B9E;&#x73B0;&#x4E86;&#x4E0A;&#x4E0B;&#x6587;&#x7BA1;&#x7406;&#x5668;&#xFF0C;&#x73B0;&#x5728;&#x5C31;&#x53EF;&#x4EE5;&#x4F7F;&#x7528; with &#x8BED;&#x53E5;&#x4E86;&#x3002;</p>
<pre><code class="lang-python"><span class="hljs-keyword">with</span> File(<span class="hljs-string">&apos;out.txt&apos;</span>, <span class="hljs-string">&apos;w&apos;</span>) <span class="hljs-keyword">as</span> f:
    print(<span class="hljs-string">&quot;writing&quot;</span>)
    f.write(<span class="hljs-string">&apos;hello, python&apos;</span>)
</code></pre>
<p>&#x8FD9;&#x6837;&#xFF0C;&#x4F60;&#x5C31;&#x65E0;&#x9700;&#x663E;&#x793A;&#x5730;&#x8C03;&#x7528; close &#x65B9;&#x6CD5;&#x4E86;&#xFF0C;&#x7531;&#x7CFB;&#x7EDF;&#x81EA;&#x52A8;&#x53BB;&#x8C03;&#x7528;&#xFF0C;&#x54EA;&#x6015;&#x4E2D;&#x95F4;&#x9047;&#x5230;&#x5F02;&#x5E38; close &#x65B9;&#x6CD5;&#x4E5F;&#x4F1A;&#x88AB;&#x8C03;&#x7528;&#x3002;</p>
<h2 id="55-&#x5B9E;&#x73B0;&#x4E0A;&#x4E0B;&#x6587;&#x7BA1;&#x7406;&#x5668;&#x7684;&#x53E6;&#x5916;&#x65B9;&#x5F0F;">5.5 &#x5B9E;&#x73B0;&#x4E0A;&#x4E0B;&#x6587;&#x7BA1;&#x7406;&#x5668;&#x7684;&#x53E6;&#x5916;&#x65B9;&#x5F0F;</h2>
<p>Python &#x8FD8;&#x63D0;&#x4F9B;&#x4E86;&#x4E00;&#x4E2A; contextmanager &#x7684;&#x88C5;&#x9970;&#x5668;&#xFF0C;&#x66F4;&#x8FDB;&#x4E00;&#x6B65;&#x7B80;&#x5316;&#x4E86;&#x4E0A;&#x4E0B;&#x6587;&#x7BA1;&#x7406;&#x5668;&#x7684;&#x5B9E;&#x73B0;&#x65B9;&#x5F0F;&#x3002;&#x901A;&#x8FC7; yield &#x5C06;&#x51FD;&#x6570;&#x5206;&#x5272;&#x6210;&#x4E24;&#x90E8;&#x5206;&#xFF0C;yield &#x4E4B;&#x524D;&#x7684;&#x8BED;&#x53E5;&#x5728; __enter__ &#x65B9;&#x6CD5;&#x4E2D;&#x6267;&#x884C;&#xFF0C;yield &#x4E4B;&#x540E;&#x7684;&#x8BED;&#x53E5;&#x5728; __exit__ &#x65B9;&#x6CD5;&#x4E2D;&#x6267;&#x884C;&#x3002;&#x7D27;&#x8DDF;&#x5728; yield &#x540E;&#x9762;&#x7684;&#x503C;&#x662F;&#x51FD;&#x6570;&#x7684;&#x8FD4;&#x56DE;&#x503C;&#x3002;</p>
<p>&#x7B2C;&#x4E8C;&#x79CD;&#x65B9;&#x5F0F;&#x9700;&#x8981;&#x4F7F;&#x7528;@contextlib&#x88C5;&#x9970;&#x5668;</p>
<pre><code class="lang-python"><span class="hljs-keyword">from</span> contextlib <span class="hljs-keyword">import</span> contextmanager

<span class="hljs-decorator">@contextmanager</span>
<span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">my_open</span><span class="hljs-params">(path, mode)</span>:</span>
    f = open(path, mode)
    <span class="hljs-keyword">yield</span> f
    f.close()
</code></pre>
<p>&#x8C03;&#x7528;</p>
<pre><code>with my_open(&apos;out.txt&apos;, &apos;w&apos;) as f:
    f.write(&quot;hello , the simplest context manager&quot;)
</code></pre><h2 id="56-&#x603B;&#x7ED3;">5.6 &#x603B;&#x7ED3;</h2>
<blockquote>
<p>Python &#x63D0;&#x4F9B;&#x4E86; with &#x8BED;&#x6CD5;&#x7528;&#x4E8E;&#x7B80;&#x5316;&#x8D44;&#x6E90;&#x64CD;&#x4F5C;&#x7684;&#x540E;&#x7EED;&#x6E05;&#x9664;&#x64CD;&#x4F5C;&#xFF0C;&#x5B9E;&#x73B0;&#x539F;&#x7406;&#x5EFA;&#x7ACB;&#x5728;&#x4E0A;&#x4E0B;&#x6587;&#x7BA1;&#x7406;&#x5668;&#x534F;&#x8BAE;(&#x5B9E;&#x73B0;__enter__&#x548C;__exit__)&#x4E4B;&#x4E0A;</p>
<p>with&#x4F7F;&#x7528;&#x4EE3;&#x7801;&#x4E2D;&#x5982;&#x679C;&#x5728;&#x6253;&#x5F00;&#x8FC7;&#x7A0B;&#x4E2D;&#x53D1;&#x751F;&#x5F02;&#x5E38;&#xFF0C;&#x9700;&#x8981;&#x4F7F;&#x7528;try-except&#x8FDB;&#x884C;&#x6355;&#x83B7;</p>
<p>Python &#x8FD8;&#x63D0;&#x4F9B;&#x4E86;&#x4E00;&#x4E2A; contextmanager &#x88C5;&#x9970;&#x5668;&#xFF0C;&#x66F4;&#x8FDB;&#x4E00;&#x6B65;&#x7B80;&#x5316;&#x4E0A;&#x4E0B;&#x7BA1;&#x7406;&#x5668;&#x7684;&#x5B9E;&#x73B0;&#x65B9;&#x5F0F;&#x3002;</p>
</blockquote>

                    
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